Check for GLES 3.0 Context Before Using 3.0 Functionality

Check for GLES 3.0 Context Before Using 3.0 Functionality

The additional testFramebufferColorEncoding() testing requires a GLES
3.0 context, but only a 2.0 context is requested.   This change will
continue to execute those tests, but only after verifying a 3.0 context
was returned.

Affects:
dEQP-EGL.functional.wide_color.window_fp16_colorspace_p3_passthrough
dEQP-EGL.functional.wide_color.pbuffer_fp16_colorspace_p3_passthrough
dEQP-EGL.functional.wide_color.window_1010102_colorspace_p3_passthrough
dEQP-EGL.functional.wide_color.pbuffer_1010102_colorspace_p3_passthrough
dEQP-EGL.functional.wide_color.window_8888_colorspace_p3_passthrough
dEQP-EGL.functional.wide_color.pbuffer_8888_colorspace_p3_passthrough
dEQP-EGL.functional.wide_color.window_888_colorspace_p3_passthrough
dEQP-EGL.functional.wide_color.pbuffer_888_colorspace_p3_passthrough

Components: EGL

Bug: 1704
Google Bug: 124910588

Change-Id: Ifc81308c569923d4d777cd5c5329568b579f1ac1